Anticoagulants

NCLEX Review Guide: Cardiovascular Pharmacology - Anticoagulants

Anticoagulant Classifications

Heparin (Unfractionated)

Mechanism: Inhibits thrombin and factor Xa by enhancing antithrombin III activity, preventing clot formation.
Administration: IV or subcutaneous only - NEVER intramuscular due to hematoma risk.
Monitoring: aPTT (activated partial thromboplastin time) - therapeutic range 1.5-2.5 times control.
Antidote: Protamine sulfate - administer slowly to prevent hypotension and bradycardia.

Low Molecular Weight Heparin (LMWH)

Examples: Enoxaparin (Lovenox), dalteparin (Fragmin) - more predictable anticoagulation than unfractionated heparin.
Advantages: Subcutaneous administration, no routine lab monitoring required, lower bleeding risk.
Injection technique: Rotate injection sites, pinch skin, inject at 90-degree angle, do not rub site.

Warfarin (Coumadin)

Mechanism: Vitamin K antagonist that inhibits synthesis of clotting factors II, VII, IX, and X.
Monitoring: PT/INR - therapeutic INR typically 2.0-3.0 (higher for mechanical heart valves).
Antidote: Vitamin K (phytonadione) - effects take 6-24 hours; fresh frozen plasma for immediate reversal.
Food interactions: Consistent vitamin K intake required - avoid dramatic changes in leafy green consumption.

Key Points

Heparin works immediately; warfarin takes 3-5 days for full effect
Bridge therapy: Start warfarin while continuing heparin until therapeutic INR achieved
All anticoagulants increase bleeding risk - monitor for signs of hemorrhage

Commonly Confused Concepts

Heparin	Warfarin
Immediate onset	Delayed onset (3-5 days)
Monitor aPTT	Monitor PT/INR
Antidote: Protamine	Antidote: Vitamin K
IV/SubQ only	Oral administration
Short half-life	Long half-life

Memory Aid: "HEPARIN"

Hospital use (IV/SubQ)
Effect immediate
Protamine antidote
APTT monitoring
Rapid reversal
Injection only
No food interactions

Clinical Scenarios

Scenario 1: Heparin Administration

Patient on heparin drip has aPTT of 120 seconds (control 30 seconds). Action: Hold heparin, notify physician - aPTT >100 indicates high bleeding risk.

Scenario 2: Warfarin Teaching

Patient asks about diet while on warfarin. Teaching point: Maintain consistent vitamin K intake - don't avoid greens, just be consistent daily.

Nursing Interventions

Assess bleeding risk: Check platelet count, PT/aPTT before administration

Monitor vital signs: Watch for hypotension, tachycardia indicating internal bleeding

Inspect for bleeding: Check urine, stool, gums, injection sites, bruising

Patient education: Soft toothbrush, electric razor, avoid NSAIDs and alcohol

Drug interactions: Many medications affect anticoagulation - verify all new prescriptions

Common Pitfalls

Never give heparin IM - causes hematomas
Don't stop warfarin abruptly - rebound hypercoagulability risk
Pregnancy: Heparin safe, warfarin contraindicated (teratogenic)

Quick Check

Self-Assessment

□ Can I identify signs of bleeding in anticoagulated patients?
□ Do I know the antidotes for heparin and warfarin?
□ Can I explain the difference between aPTT and INR monitoring?
□ Do I understand warfarin food and drug interactions?
□ Can I teach proper LMWH injection technique?

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Anticoagulants

NCLEX Review Guide: Cardiovascular Pharmacology - Anticoagulants

Anticoagulant Classifications

Heparin (Unfractionated)

Low Molecular Weight Heparin (LMWH)

Warfarin (Coumadin)

Key Points

Commonly Confused Concepts

Memory Aid: "HEPARIN"

Clinical Scenarios

Scenario 1: Heparin Administration

Scenario 2: Warfarin Teaching

Nursing Interventions

Common Pitfalls

Quick Check

Self-Assessment

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제안하기

컨텐츠 수정하기

Anticoagulants

NCLEX Review Guide: Cardiovascular Pharmacology - Anticoagulants

Anticoagulant Classifications

Heparin (Unfractionated)

Low Molecular Weight Heparin (LMWH)

Warfarin (Coumadin)

Key Points

Commonly Confused Concepts

Memory Aid: "HEPARIN"

Clinical Scenarios

Scenario 1: Heparin Administration

Scenario 2: Warfarin Teaching

Nursing Interventions

Common Pitfalls

Quick Check

Self-Assessment